On Tue, Dec 20, 2022 at 6:08 AM Adam Ford <aford173@xxxxxxxxx> wrote:
>
> The imx219 camera is capable of either two-lane or four-lane
> operation. When operating in four-lane, both the pixel rate and
> link frequency change. Regardless of the mode, however, both
> frequencies remain fixed.
>
> Helper functions are needed to read and set pixel and link frequencies
> which also reduces the number of fixed registers in the table of modes.
>
> Signed-off-by: Adam Ford <aford173@xxxxxxxxx>
Gentle nudge on this.
> ---
> V4: Restore check for nr_of_link_frequencies and update commit message
> V3: Keep the helper function doing the link and lane parsing to
> keep th probe function small.
>
> V2: Replace if-else statements with ternary operator
> Fix 4-lane Link Rate.
> Fix checking the link rate so only the link rate for
> the given number of lanes is permitted.
>
> diff --git a/drivers/media/i2c/imx219.c b/drivers/media/i2c/imx219.c
> index 7f44d62047b6..b5fa4986470a 100644
> --- a/drivers/media/i2c/imx219.c
> +++ b/drivers/media/i2c/imx219.c
> @@ -42,10 +42,16 @@
> /* External clock frequency is 24.0M */
> #define IMX219_XCLK_FREQ 24000000
>
> -/* Pixel rate is fixed at 182.4M for all the modes */
> +/* Pixel rate is fixed for all the modes */
> #define IMX219_PIXEL_RATE 182400000
> +#define IMX219_PIXEL_RATE_4LANE 280800000
>
> #define IMX219_DEFAULT_LINK_FREQ 456000000
> +#define IMX219_DEFAULT_LINK_FREQ_4LANE 363000000
> +
> +#define IMX219_REG_CSI_LANE_MODE 0x0114
> +#define IMX219_CSI_2_LANE_MODE 0x01
> +#define IMX219_CSI_4_LANE_MODE 0x03
>
> /* V_TIMING internal */
> #define IMX219_REG_VTS 0x0160
> @@ -299,6 +305,10 @@ static const s64 imx219_link_freq_menu[] = {
> IMX219_DEFAULT_LINK_FREQ,
> };
>
> +static const s64 imx219_link_freq_4lane_menu[] = {
> + IMX219_DEFAULT_LINK_FREQ_4LANE,
> +};
> +
> static const char * const imx219_test_pattern_menu[] = {
> "Disabled",
> "Color Bars",
> @@ -474,6 +484,9 @@ struct imx219 {
>
> /* Streaming on/off */
> bool streaming;
> +
> + /* Two or Four lanes */
> + u8 lanes;
> };
>
> static inline struct imx219 *to_imx219(struct v4l2_subdev *_sd)
> @@ -936,6 +949,13 @@ static int imx219_get_selection(struct v4l2_subdev *sd,
> return -EINVAL;
> }
>
> +static int imx219_configure_lanes(struct imx219 *imx219)
> +{
> + return imx219_write_reg(imx219, IMX219_REG_CSI_LANE_MODE,
> + IMX219_REG_VALUE_08BIT, (imx219->lanes == 2) ?
> + IMX219_CSI_2_LANE_MODE : IMX219_CSI_4_LANE_MODE);
> +};
> +
> static int imx219_start_streaming(struct imx219 *imx219)
> {
> struct i2c_client *client = v4l2_get_subdevdata(&imx219->sd);
> @@ -953,6 +973,13 @@ static int imx219_start_streaming(struct imx219 *imx219)
> goto err_rpm_put;
> }
>
> + /* Configure two or four Lane mode */
> + ret = imx219_configure_lanes(imx219);
> + if (ret) {
> + dev_err(&client->dev, "%s failed to configure lanes\n", __func__);
> + goto err_rpm_put;
> + }
> +
> /* Apply default values of current mode */
> reg_list = &imx219->mode->reg_list;
> ret = imx219_write_regs(imx219, reg_list->regs, reg_list->num_of_regs);
> @@ -1184,6 +1211,11 @@ static const struct v4l2_subdev_internal_ops imx219_internal_ops = {
> .open = imx219_open,
> };
>
> +static unsigned long imx219_get_pixel_rate(struct imx219 *imx219)
> +{
> + return (imx219->lanes == 2) ? IMX219_PIXEL_RATE : IMX219_PIXEL_RATE_4LANE;
> +}
> +
> /* Initialize control handlers */
> static int imx219_init_controls(struct imx219 *imx219)
> {
> @@ -1205,15 +1237,16 @@ static int imx219_init_controls(struct imx219 *imx219)
> /* By default, PIXEL_RATE is read only */
> imx219->pixel_rate = v4l2_ctrl_new_std(ctrl_hdlr, &imx219_ctrl_ops,
> V4L2_CID_PIXEL_RATE,
> - IMX219_PIXEL_RATE,
> - IMX219_PIXEL_RATE, 1,
> - IMX219_PIXEL_RATE);
> + imx219_get_pixel_rate(imx219),
> + imx219_get_pixel_rate(imx219), 1,
> + imx219_get_pixel_rate(imx219));
>
> imx219->link_freq =
> v4l2_ctrl_new_int_menu(ctrl_hdlr, &imx219_ctrl_ops,
> V4L2_CID_LINK_FREQ,
> ARRAY_SIZE(imx219_link_freq_menu) - 1, 0,
> - imx219_link_freq_menu);
> + (imx219->lanes == 2) ? imx219_link_freq_menu :
> + imx219_link_freq_4lane_menu);
> if (imx219->link_freq)
> imx219->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;
>
> @@ -1308,7 +1341,7 @@ static void imx219_free_controls(struct imx219 *imx219)
> mutex_destroy(&imx219->mutex);
> }
>
> -static int imx219_check_hwcfg(struct device *dev)
> +static int imx219_check_hwcfg(struct device *dev, struct imx219 *imx219)
> {
> struct fwnode_handle *endpoint;
> struct v4l2_fwnode_endpoint ep_cfg = {
> @@ -1328,10 +1361,12 @@ static int imx219_check_hwcfg(struct device *dev)
> }
>
> /* Check the number of MIPI CSI2 data lanes */
> - if (ep_cfg.bus.mipi_csi2.num_data_lanes != 2) {
> - dev_err(dev, "only 2 data lanes are currently supported\n");
> + if (ep_cfg.bus.mipi_csi2.num_data_lanes != 2 &&
> + ep_cfg.bus.mipi_csi2.num_data_lanes != 4) {
> + dev_err(dev, "only 2 or 4 data lanes are currently supported\n");
> goto error_out;
> }
> + imx219->lanes = ep_cfg.bus.mipi_csi2.num_data_lanes;
>
> /* Check the link frequency set in device tree */
> if (!ep_cfg.nr_of_link_frequencies) {
> @@ -1340,7 +1375,8 @@ static int imx219_check_hwcfg(struct device *dev)
> }
>
> if (ep_cfg.nr_of_link_frequencies != 1 ||
> - ep_cfg.link_frequencies[0] != IMX219_DEFAULT_LINK_FREQ) {
> + (ep_cfg.link_frequencies[0] != ((imx219->lanes == 2) ?
> + IMX219_DEFAULT_LINK_FREQ : IMX219_DEFAULT_LINK_FREQ_4LANE))) {
> dev_err(dev, "Link frequency not supported: %lld\n",
> ep_cfg.link_frequencies[0]);
> goto error_out;
> @@ -1368,7 +1404,7 @@ static int imx219_probe(struct i2c_client *client)
> v4l2_i2c_subdev_init(&imx219->sd, client, &imx219_subdev_ops);
>
> /* Check the hardware configuration in device tree */
> - if (imx219_check_hwcfg(dev))
> + if (imx219_check_hwcfg(dev, imx219))
> return -EINVAL;
>
> /* Get system clock (xclk) */
> --
> 2.34.1
>
